Answer:
Step-by-step explanation:
This is an allusion.
It makes reference to a Biblical character that was swallowed by a large fish (some people say it was a whale. It wasn't). You can read the Old Testament version by reading Jonah. It isn't very long and should take you only about 1/2 hour.
It is a very apt allusion, because Jonah had to pray to the Lord begging for forgiveness before he was released from the stomach of the creature. I doubt any of the seamen knew what happened to him until he was released at the behest of the Lord.
This quotation conveys the same idea. No one knew there was life behind the wall until they heard the frantic noise.